The use of bipolar GaAs ICs is evaluated with respect to the AN/APS-137 Inverse Synthetic Aperture Radar (ISAR) system on the basis of power and size requirements and resolution quality. System upgrades include a software change and other modifications in the receiver weapon-replaceable assembly (WRA). A block diagram of the receiver WRA is given which describes the modified circuitry after the insertion of GaAs ICs. A 250-MHz technology is required to achieve a 200 MHz sampling rate with 80-percent reliability derating, and the GaAs satisfies this requirement. The IC designs are described with particular attention given to the data buffer and delay generator and related operational requirements. It is shown that the two GaAs ASICs using the Standard Gate structure can provide the resolution improvements required for the AN/APS-137 radar ISAR range.